//
//  EtagStorage.swift
//  DuckDuckGo
//
//  Copyright © 2019 DuckDuckGo. All rights reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
//

import Common
import Foundation
import Configuration
import os.log

public protocol BlockerListETagStorage {

    func saveEtag(_ etag: String, for configuration: Configuration)
    func loadEtag(for configuration: Configuration) -> String?

}

public struct UserDefaultsETagStorage: BlockerListETagStorage {

    private let defaults = UserDefaults(suiteName: "\(Global.groupIdPrefix).app-configuration")

    public init() { }

    public func loadEtag(for configuration: Configuration) -> String? {
        let etag = defaults?.string(forKey: configuration.storeKey)
        Logger.general.debug("Stored etag for \(configuration.storeKey) \(etag ?? "nil")")
        return etag
    }

    public func saveEtag(_ etag: String, for configuration: Configuration) {
        defaults?.set(etag, forKey: configuration.storeKey)
    }

}
